1. Field of the Invention
The present invention relates to a lighting unit used for input/output device, more particularly to a lighting unit used for keyboards. The lighting unit can be a luminary that is capable to illuminate hot keys of the keyboard.
2. Description of the Prior Art
To improve visual effect or fun of using computers, a single independent light source is added under each key of input/output device. Usually, a single independent Light Emitting Diode/LED is installed in the key cap of each key. In other words, the input/output device must use LEDs with the same counts as that of the keys and, therefore, consume more power and increase production costs.
U.S. Pat. No. 6,179,432 disclosed a lighting unit used in a keyboard. This keyboard has a base and a plurality of keys with key caps. An Electroluminescence (EL) is clamped between the base and each key cap. However, EL has a short average life and is more expensive than LED, and, therefore, is not practical for the electronic industry for which the cost is the most important operation factor.
To solve this problem, the present invention provides a lighting unit that is applicable to various types of input/output device and capable to illuminate the keys.
The primary object of the present invention is to provide a lighting unit used for input/output device. With the lighting unit of the present invention, only a minimum number of luminaries are needed to illuminate all keys and the cost is lowered down.
The lighting unit of the present invention comprises at least a trough and a plurality of slots on a light penetration member attached at the bottom of a base, and at least a LED disposed in the trough. Fasteners are attached to the end of the feet of each key to join the key to the slots on the light penetration member. Each key is capable to move up and down freely with respect to the base. Since the LED connects to a power supply, the LED lights. All relevant keys will have an appropriate luminosity.
Another object of the present invention is to provide a lighting unit that is applicable to various types of input/output device.